Such apparatuses are used for example, but in no way exclusively, for aligning printed sheets along at least one edge, with sufficient accuracy, one above the other, with the result that the stack can then be trimmed at the edges. In the case of a fair number of printed products, for example notes of value provided with registration numbers, it is necessary, once the sheets have been printed, to maintain the sequence of the sheets in the stack-forming pile.
EP 06 14 840 A1 discloses an apparatus which is designed in the manner of a vibrating table. A supporting table is provided for this vibrating table, lateral stops being arranged on at least two, adjacent sides of the supporting table and it being possible for these stops to come into abutment against the side edges of the sheets. In order to align the stack of sheets arranged one above the other, the stack is set down on the supporting table and the latter is then inclined in the direction of the two stops to the extent where the side edges of the sheets come into abutment against the stops on account of gravitational force. The vibrating table is then made to vibrate in order thus to loosen the stack of sheets and to allow an aligning movement of the individual sheets relative to one another.
DE 68 09 156 U discloses an apparatus which is intended for aligning items of mail and in the case of which an imbricated stream is aligned to form a stack.
U.S. Pat. No. 4,369,959 A discloses an apparatus for aligning an edge of a plurality of sheets arranged one above the other on a supporting table one side of which a leading-edge stop is arranged. The apparatus contains a sheet feeder, by means of which the sheets are conveyed to the leading-edge stop.
DE 42 36 839 A discloses a carrying plate on which the sheets are set down with non-aligned leading edges and are conveyed from the carrying plate to form an imbricated stream with underlap imbrication.
U.S. Pat. No. 4,570,918 A describes a blowing device which blows air between sheets from the trailing edges thereof.
DE 198 27 531 A1 discloses a feeder with two leading-edge stops and a side lay arranged on its table.